Pulse Pal
Bpod can control neural stimulation by triggering Pulse Pal, an open source pulse train generator for physiology, optogenetics and behavior. Pulse Pal is developed and maintained by Sanworks LLC.
Here are some useful links to get started:
Wiki:
https://sites.google.com/site/pulsepalwiki/home
Repository:
https://github.com/PulsePal/PulsePal.git
Publication:
http://journal.frontiersin.org/article/10.3389/fneng.2014.00043/abstract